Enables estrogen receptor activity. Involved in several processes, including cellular chemical homeostasis; positive regulation of cell communication; and positive regulation of nitrogen compound metabolic process. Located in cytoplasm; hippocampal mossy fiber to CA3 synapse; and plasma membrane. Is expressed in embryo; metanephros; and pituitary gland. Orthologous to human GPER1 (G protein-coupled estrogen receptor 1). [provided by Alliance of Genome Resources, Apr 2022]